Tooth decay caused by the effect of plaque and bacteria on tooth enamel is steadily being reduced as the prime cause of tooth loss. Fluorides put in drinking water or topically applied as well as new synthetic coatings to be applied to the teeth have respectively toughened the enamel to resist decay and shielded the enamel so that in the very near future decay will not occur on the enamel surfaces. Brushing the teeth as it is presently done to remove plaque and bacteria will not be necessary to prevent decay. Brushing of the enamel surfaces will only be done to gain a general feeling of cleanliness of the teeth and mouth. The focus of proper dental care will shift to the prevention of periodontal disease and to the gum and to bacteria under the sulcus where the root surface is vulnerable to decay because it is not protected by enamel. Gums will have to be massaged to suffuse them with blood to keep them from receding. Bacteria will have to be removed from this unprotected area as well as from under the sulcus. The importance of addressing the gum for proper dental care was first taught by U.S. Pat. No. 2,845,649 which discloses the idea of soft toothbrush bristles and the importance of gum massage in oral health care. Until relatively recently, up and down brushing, i.e., vertical stroking, was the preferred and most widely recommended dental cleaning technique to clean the enameled surfaces. When this method is used with a conventional toothbrush, the gums are inadvertently massaged (stimulated) as the brushing surface passes beyond the upper and lower gumlines. This gum massage should stimulate the gums and should be beneficial for gum health. However, it was found that this vertical stroking pushed the gum away from teeth and forced food into the space between the teeth and gums thus contributing to periodontal disease and to cavities below the gum line. Such damage to the gums and teeth can be eliminated by brushing with a toothbrush having soft bristles with rounded ends and by using a motion that is primarily back and forth, i.e., a horizontal stroking technique. Consequently, horizontal stroking is now the preferred dental cleaning technique.
A shortcoming of horizontal stroking with a conventional toothbrush is that unless the user is schooled in the proper use of the brush and uses it in that way, proper cleaning and stimulation of the gums will not be accomplished. In other words, casual horizontal brushing with conventional toothbrushes does not result in properly stimulated gums and thus this very critical part of good dental hygiene is lost. This is particularly harmful to the gums and teeth in the buccal corridor, that is, in the space between the cheek, gums and teeth, because this area is not ordinarily stimulated by normal eating and chewing.
Another shortcoming of conventional toothbrush design is that it fails to encourage proper brushing technique as illustrated by the Bass (Stillman) toothbrushing technique which requires the bristles to be angled at 45.degree. toward the gumline. A current textbook describing this technique is Glickman's Clinical Periodontology--Ferman A. Carranza Jr. Dr. Odont--5th edition, 1979, pages 729-738. Unless the bristles are consciously angled toward the gumline, the area under the sulcus on the tooth root will not be swept clean of bacteria, a basic cause of tooth decay and periodontal disease.
Another shortcoming of the conventional toothbrush is that the soft bristles suitable for gum contact are less effective for cleaning the hard tooth surfaces and if one pushes hard to get a better cleaning action, it splays the bristles and results in a reduction in the overall effectiveness of all brushing action.